Field of the Invention
The present invention relates to a vehicle seat, which has a base structure with adjustable side pieces.
Description of the Background Art
“Function-integrated, bionic car seats” are known from the prior art. The particular feature of these seats lies in the design of the backrest, which utilizes the fin ray principle. The use of this principle and the basic structure, the so-called fin ray structure, have already been described in EP 1 040 999 A2 for the construction of structural elements, such as backrests and seat areas.
The fin ray principle can be observed in fish. It is based on the special structure of the fin rays of fish. When a point is pressed, the principle causes the fin ray to move opposite to this pressure direction. The fin ray reacts to the pressure with counterpressure. This becomes possible because of the special structure of the fin ray with two flexible braces, which converge at a tip and there grow together solidly. Transverse braces, which keep the flanks at a distance and allow elastic movements, are located between the two elastic flanks. If the tail ray is held firmly at the base, which is opposite to the tip, and the middle of the fin blade is pressed with a finger, the fin tip contrary to expectations moves opposite to the pressing direction of the finger.
This operating principle was already realized technically in a backrest structure of a car seat in the following manner: Two flexible flanks made of thermoplastic fiberglass composite (a so-called organic sheet) form the front and back of the backrest. These are attached at the bottom to the backrest base, run together tapering upwards, where their ends are connected. Braces attached in an articulated manner to the flanks connect the front and back sides and keep these at a distance. Such a backrest also provides support in the lumbar area, yields in the shoulder region mostly toward the back, and thereby simultaneously reduces the distance of a head cushion of a head restraint to the head of a seat occupant. In large displacements, as may also occur, for example, in a rear-end collision, thus whiplash injury can be effectively countered with the aid of such a backrest structure. Thus, an anti-whiplash effect in the head area can be achieved with such a backrest structure.
A vehicle seat that utilizes the fin ray principle is described in the publication DE 10 2005 054 125 B3. The backrest frame of the vehicle seat comprises a construction built on the fin ray principle in a frame-like fashion. The construction comprises a rigid rear wall, a flexibly formed plate-like front wall, and transverse braces arranged between them. The transverse braces extend in their longitudinal direction along the vehicle seat width direction. The front wall and rear wall, in contrast, have a longitudinal extension in the vehicle height direction. The publication provides a backrest of a vehicle seat, which can be deformed in a simple way by using the fin ray principle both in the lumbar and in the shoulder region with mutual interdependence.
A vehicle seat with a backrest is known from the publication DE 10 2009 033 883 A, which has a supporting rod structure at least in a lateral middle area for at least one cushion part supporting the seat user. The rod structure is fastened at the bottom to a supporting part, which is supported on the seat part of the vehicle seat. The rod structure between a front and rear support wall has in each case supporting rods arranged at a vertical distance from one another. The rod structure forms a free space open at least at the bottom or on the side. An upwardly or laterally protruding support element, which is not or at most slightly deformable and projects from the bottom or laterally into the free space of the rod structure, is attached to the supporting part. With greater stress on the backrest toward the back or toward the front, the supporting element either immediately or after a predetermined elastic deformation of the rod structure in the lower area comes to rest against the facing front or rear support wall and/or at least one supporting rod and supports the affected front support wall and/or supporting rod which is in contact. Publication DE 10 2009 033 883 A1 in its introduction refers to DE 10 2005 054 125 B3, which describes a backrest frame, which is made frame-like with consideration of the fin ray principle. The bar structure of the backrest which is described in the publication DE 10 2009 033 883 A1 also utilizes the fin ray principle, whereby side cushion parts supporting a seat user are arranged to the side of the bar structure but these cannot be adjusted further relative to the bar structure.